Yahoo Mail - what happened to GBS?

Yahoo's YUI has a great idea called "Graded Browser Support". Read about it at http://developer.yahoo.com/yui/articles/gbs/

In short, it says "we know specifically what browsers suck, and specifically what browsers don't suck, and if we don't know about it, we assume you're a geek and your browser doesn't suck." Or in their terms, C-Grade, A-Grade, and X-Grade.

The problem is that Yahoo Mail - generally a great product - isn't on board. They're about to release their "All-New" new mail ui. And they've sent out lots of messages about it, to avoid surprising users. Yet their browser detection fails to figure out that Seamonkey - a Gecko-based browser, pretty much the same as Firefox internally - should get the fancy stuff. By my reading of GBS, Seamonkey should be X-Grade, which gets all js and css. But instead they give me "Upgrade to a supported browser!"

I understand that they don't want to answer tons of support crap about "it doesn't work with IE6!!". That's the whole point of GBS. I know the risks. The current "all-new" yahoo mail also doesn't recognize seamonkey, but it at least gives a "go ahead anyway" option. Now could they just do the same and let me at least try it with my almost-Firefox browser?

The difference

The difference between perl programmers and java programmers, presented with the same problem:
The perl programmer thinks, "I can solve that in one line with regexp".
The java programmer thinks, "I can solve that by adding in a new framework."